Hollow metal door



Nov. 12, 1935. H. w. SCHWARTZ HOLLOW METAL DOOR Filed Feb. 8,

50 engage with t continuous clips 3 which are teristics of the invention and the present em- 5 Patented Nov. 12, 1935 2,020,337

UNITED STATES PATENT OFFICE nontovzfiz 'r zn DOOR I Howard W. Schwartz, New York, N. Y. Application February 8, 1934, Serial No. 210,26:

- 8 Claims. (01. 189- 46) This invention relates to hollow metal door and expanded holes in ribs 4 are indicated at I constructions and more particularly to flush type while the spot welding projections are 'desighollow metal door constructions. nated at 8. These holes I and projections 8 oc- One object of this invention is to provide a our at proper intervals along each of ribs 4 as Ii strong construction that will hold rigid under indicated by the asterisks which denote the spot 5 extreme operating stresses such as are usual to welded points of connection between surface high speed power operation. 7 sheets I and 2 and ribs 4.

Another object of this invention is to provide The spot welded points along both top and. I a simple door construction which is adaptable to bottom edges of door are indicated by asterisks II) be spot-welded through its entire thickness after which in turn are designated by 9. These spot- 10 assembly. welds connect metal sheets I and 2 to top and Another object of this invention is to permit bottom channels 6. the use of flat electrodes in the spot welding ma- The are welded connections of metal sheets I chine and cause the outside surfaces of the sheet and 2 are indicated adjacent top and bottom I to remain flat and true without depressions or edges of the door on Fig. 1 at Ill.

raised blisters on the surfaces. It will be observed that the spacing bars 5 are Another object of this invention is t9 reduce notched to a depth at each edge to leave a net the amount of gas or arc welding to a minimum width equal to the width of the punched and exand so eliminate most of the distortion caused panded holes I at all points of intersection with by such welding. vertical ribs 4 and that during the assembly of 20 Other objects of this invention include the novel said spacing bars 5 with vertical ribs 4 the spacfeatures and details of construction of the various ing bars 5 are inserted through punched and exparts and combinations of parts disclosed in this panded' holes I, in ribs 4, flatwise and then turned application. at right-angles to complete the interlocking of The above and other objects will appear from the two series of bars, with the-notches in spac- 25 the following description, appended claims and ing bars 5 engaging with and holding ribs 4 in accompanying drawing forming a part of this accurately spaced positions. specification. When this operation is completed the whole grid Referring to the drawing in which one comformed by the said bars 5 and ribs 4 is inserted 80 plete method of carrying out the invention is endwise between the metal sheets I and 2, poshown for illustrative purposes: sitioned accurately, and then through-spotweld- Fig. 1 is an elevation showing one side of '9. ed in place at all expanded welding points 8 which complete flush type hollow metal door embodyoccur at proper intervals along each edge of each ing my invention. vertical rib 4 to interior sides of metal sheets Fig. 2 is an enlarged vertical sectional view I and 2.

at line AA through the lower portion of the The end channels 6 at top and bottom of the door as indicated in Fig. 1. door are also spotwelded to the interior surfaces Fig. 3 is an enlarged horizontal sectional view of sheets I and 2 at welding points 9. at line B-B as indicated on Fig. 1. The seams between sheets I and 2 at each 40 4 is an enlarged View m fi to 3 and side, top and bottom, are are welded together as Shows another method of jommg the Surface indicated at Ill and then are ground off smooth of the door together, as a final step in the fabrication of the door.

Like numerals refer to like parts throughout In Fig 4, the locked seam 3a is shown as an i im gggg h of my invention Shown in alternative connection between sheets I and 2, 5 the drawing, I indicates'the metal sheet on near ,Efi g f gg g gg gg gjgggzfi g ifjg side center, while 2 designates the metal sheet of cific s than g herein Set forth g the far side, which is returned at side edges to meet the metal Sheet on the near side and to departing from the spirit and essential characslidecl in place from top at bottom of d r bodiment is therefore to be considered in all refore top and bottom channels 6 are placed. spects as illustrative and not restrictive, and all At 4- the vertical ribs are shown, while 5 inchanges coming within th m n n n q vadicates the horizontal spacing bars adjacent top, lency range of the appended claims are intended bottom, and center of the door. The punched to be embraced'therein.

I claim:

1. A hollow metal door construction comprising: a main surface sheet which has both side edges returned in u-shapes and with both extreme returned edges again returned in shorter, narrower U-shapes, a supplementary surface sheet with each side edge being returned in narrow U-shapes and dimensioned to fit between the edges of the returned portions of the main surface sheet, a doubly returned U-clip that binds the main surface sheet and the supplementary surface sheet together continuously from a pointnear the bottom of the door to a point near the top end of the door in lines spaced from each side edge of the door on one surface, and vertically alined bars with spaced oppositely punch expanded points adapted for spotwelding to the interior surfaces of the main surface sheet and the supplementary surface sheet, with the aforesaid vertically alined bars spaced apart with interlocking cross bars.

2. A hollow metal door construction embodying two metal sheets, vertically alined bars with spaced oppositely punch expanded points adapted for contact welding to the interior surfaces of the said two metal sheets, and spaced apart at intervals with interlocking cross bars.

3. A door panel construction comprising: spaced-apart front and rear sheet-metal portions; spaced-apart bracing-ribs extending the main distance between opposite edges of the doorpanel and between the front and rear sheetmetal portions; each bracing-rib having two sets of spaced-apart projections; one set of projections being welded to the front sheet-metal portion and the other set of projections being welded to the rear sheet-metal portion; the portions of the surfaces of the bracing-ribs between the projections and nearest the sheet-metal portions being well spaced away from the latter.

4. A door panel construction comprising: spaced-apart front and rear sheet-metal portions; spaced-apart, flat-bar bracing-ribs extending the main distance between opposite edges of the door panel and betwee and substantially at right angles to, the front and rear sheet-metal portions; each bracing-rib having two sets of spaced-apart projections; one set of projections being welded to the front sheet-metal portion and the other set of projections being welded to the rear sheet-metal portion; the portions of the edge-surfaces of the bracing-ribs between the projections and nearest the sheet-metal portions being well spaced away from the latter.

5. A door panel construction comprising: spaced-apart front and rear sheet-metal portions; spaced-apart, fiat-bar bracing-ribs extending the main distance between "opposite edges of the door panel and between, and substantially s at right angles to, the front and rear sheet-metal portions; each bracing-rib having two sets ,of spaced-apart projections; one set of projections being welded to the front sheet-metal portion and the other set of projections being welded to 10 the rear sheet-metal portion; the portions of the edge-surfaces of the bracing-ribs between the projections and nearest the sheet-metal portions being well spaced away from the latter the bracing-ribs having spaced-apart sets of holes 15 through which spacing-bars extend. 6. A door panel construction comprising: spaced-apart front and rear sheet-metal portions; spaced-apart, flat-bar bracing-ribs extending the main distance between opposite edges 20 of the door panel and between, and substantially at right angles to, the front and rear sheet-metal portions; each bracing-rib having two sets of spaced-apart projections, the projections of one set being substantially opposite corresponding 85 projections of the other set; one set of projections being welded to the front sheet-metal portion and the other set of projections being welded to the rear sheet-metal portion; the portions of the edge-surfaces of the bracing-ribs between the 80 projections and nearest the sheet-metal portions being well spaced away from the latter.

7. A door panel construction comprising: spaced-apart metal sheets joined together along meeting edges extending the length of the door 86 panel by juncture seams; a short portion of each of the opposite ends of each juncture seam being formed by welding the adjacent parts of adjoining metal sheets; and the intermediate portion of each juncture seam being formed by fold-lock- 40 ing the adjacent parts of adjoining metal sheets.

8. A door panel construction comprising: spaced-apart metal sheets joined together along meeting edges extending along one face of, and the length of the door panel by juncture seams; 45 a short portion of each of the opposite ends of each juncture seam being formed by welding the adjacent parts of adjoining metal sheets; and the intermediate portion of each juncture seam being formed by fold-locking the adjacent parts of adjoining metal sheets. V

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